package com.lyz.myself.config.wx;

/**
 * @program: myself
 * @Date: 2019/2/21 17:31
 * @Author: lyz
 * @Description:
 */

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.security.AlgorithmParameters;
import java.security.Security;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.util.encoders.Base64;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;

    public class XcxUtils {

        /**
         * 获取微信小程序 session_key 和 openid
         *
         * @author zhy
         * @param code
         *            调用微信登陆返回的Code
         * @return
         */
        public static JSONObject getSessionKeyOropenid(String code) {
            // 微信端登录code值
            String wxCode = code;
            String requestUrl = UserConstantInterface.WX_LOGIN_URL;// 请求地址

            Map<String, String> requestUrlParam = new HashMap<String, String>();
            requestUrlParam.put("appid", UserConstantInterface.WX_LOGIN_APPID); // 开发者设置中的appId
            requestUrlParam.put("secret", UserConstantInterface.WX_LOGIN_SECRET); // 开发者设置中的appSecret
            requestUrlParam.put("js_code", wxCode); // 小程序调用wx.login返回的code
            requestUrlParam.put("grant_type", UserConstantInterface.WX_LOGIN_GRANT_TYPE); // 默认参数

            // 发送post请求读取调用微信 https://api.weixin.qq.com/sns/jscode2session
            // 接口获取openid用户唯一标识
            JSONObject jsonObject = JSON.parseObject(sendPost(requestUrl, requestUrlParam));
            // System.out.println(jsonObject);
            return jsonObject;
        }

        /**
         * 解密用户敏感数据获取用户信息
         *
         * @author zhy
         * @param sessionKey
         *            数据进行加密签名的密钥
         * @param encryptedData
         *            包括敏感数据在内的完整用户信息的加密数据
         * @param iv
         *            加密算法的初始向量
         * @return
         */
        public static JSONObject getUserInfo(String encryptedData, String sessionKey, String iv) {
            System.out.println("encryptedData"+encryptedData+"sessionKey"+sessionKey+"iv"+iv);
            // 被加密的数据
            byte[] dataByte = Base64.decode(encryptedData);
            System.out.println("dataByte");
            // 加密秘钥
            byte[] keyByte = Base64.decode(sessionKey);
            System.out.println("keyByte");
            // 偏移量
            byte[] ivByte = Base64.decode(iv);
            System.out.println("ivByte");
            try {
                // 如果密钥不足16位，那么就补足. 这个if 中的内容很重要
                int base = 16;
                if (keyByte.length % base != 0)
                {
                    int groups = keyByte.length / base + (keyByte.length % base != 0 ? 1 : 0);
                    byte[] temp = new byte[groups * base];
                    Arrays.fill(temp, (byte) 0);
                    System.arraycopy(keyByte, 0, temp, 0, keyByte.length);
                    keyByte = temp;
                }
                // 初始化
                Security.addProvider(new BouncyCastleProvider());
                Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding", "BC");
                SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");
                AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES");
                parameters.init(new IvParameterSpec(ivByte));
                cipher.init(Cipher.DECRYPT_MODE, spec, parameters);// 初始化
                byte[] resultByte = cipher.doFinal(dataByte);
                if (null != resultByte && resultByte.length > 0)
                {
                    String result = new String(resultByte, "UTF-8");
                    return JSON.parseObject(result);
                }
            } catch (Exception e) {
                System.out.println(e);
            }
            return null;
        }

        /**
         * 向指定 URL 发送POST方法的请求
         *
         * @param url
         *            发送请求的 URL
         * @return 所代表远程资源的响应结果
         */
        public static String sendPost(String url, Map<String, ?> paramMap) {
            PrintWriter out = null;
            BufferedReader in = null;
            String result = "";

            String param = "";
            Iterator<String> it = paramMap.keySet().iterator();

            while (it.hasNext()) {
                String key = it.next();
                param += key + "=" + paramMap.get(key) + "&";
            }
            try {
                URL realUrl = new URL(url);
                // 打开和URL之间的连接
                URLConnection conn = realUrl.openConnection();
                // 设置通用的请求属性
                conn.setRequestProperty("accept", "*/*");
                conn.setRequestProperty("connection", "Keep-Alive");
                conn.setRequestProperty("Accept-Charset", "utf-8");
                conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
                // 发送POST请求必须设置如下两行
                conn.setDoOutput(true);
                conn.setDoInput(true);
                // 获取URLConnection对象对应的输出流
                out = new PrintWriter(conn.getOutputStream());
                // 发送请求参数
                out.print(param);
                // flush输出流的缓冲
                out.flush();
                // 定义BufferedReader输入流来读取URL的响应
                in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
                String line;
                while ((line = in.readLine()) != null) {
                    result += line;
                }
            } catch (Exception e) {
                System.out.println(e);
            }
            // 使用finally块来关闭输出流、输入流
            finally {
                try {
                    if (out != null)
                    {
                        out.close();
                    }
                    if (in != null)
                    {
                        in.close();
                    }
                } catch (IOException ex) {
                    ex.printStackTrace();
                }
            }
            return result;
        }

}
